1. Field of the Invention
This invention relates to a variably stackable tray system. It relates more particularly to a tray system or package for use in connection with sterilizing, delivering and presenting surgical instruments and materials in an aseptic condition prior to surgery and preventing contamination from those instruments following surgery.
It is normal procedure to provide appropriate types and quantities of surgical instruments and materials for a specific surgical procedure as a unitary package that has been sterilized previously. Prior to or during an operation, the instruments and materials are removed from the package and laid out on a Mayo table or other surface so that they are readily accessible to the surgeon performing the operation.
2. Description of the Prior Art
Conventionally, an instrument package includes an outer container for enclosing trays arranged in layers or in a stack within the container. The open top of the container is invariably closed by a cover or lid which may be latched to the container so that the container contents are protected and maintained in a sterile condition when a package is transported from the sterilizer to the operating area.
Preferably, the instrument package for a particular procedure has the various instruments and materials laid out on the trays in the order in which they will be used for that procedure. In other words, the group of instruments that will be used first will be in the uppermost tray in the container. When those instruments have been used or are no longer required, that uppermost tray is removed exposing the group of instruments presented on the underlying tray. When that second group of instruments is no longer required, that second tray is removed exposing the instruments in the next tray, and so on down to the lowermost tray in the container. When the surgical procedure is completed, the instruments and trays may be returned to the container and the container closed so that the entire package can be carried to a cleaning area without risk of contamination from the instruments therein. U.S. Pat. No. 5,540,901 shows a sterilization tray system or package of this general type.
While the sterilization tray system just described is quite satisfactory in many respects and may be used in many surgical procedures, it does not take into account that some procedures may require the use of more instruments and materials than others. In other words, for a complicated surgical procedure, the outer container must be able to accommodate several instrument trays stacked within the container, while a simple surgical procedure may only require one or two instrument trays within the outer container. This means that an outer container capable of accommodating the number of trays required by the most complicated procedure must be used even though a lesser number of instruments may suffice for most operations. Clearly, then, the overall cost and the size of many, if not most, instrument packages are larger than they need be. Also, the height of the outer container limits the maximum number of trays that can be accommodated by the container so that the usual tray system cannot be used for that rare surgical procedure that may require an unusually large number of instruments and/or materials.